Device for balancing bodies adapted for rising and falling movements



June 2, 1931.

H. R. WEBB ET AL DEVICE FOR BALANCING BODIES ADAPTED FOR RISING AND FALLING MOVEMENTS Filed June 8, 1929 Patented June 2,1931

UNITED STATES PATENT OFFICE HARRY RILEY WEBB AND HARRY NEWTON WEBB, OF GBANT'HAM, ENGLAND DEVICE FOR BALANCING BODIES ADAP'IED FOR RISING AND FALLING MOVEMENTS Application filed June 8, 1929, Serial No. 369,477, and in Great Britain February 5, 1929.

10 cordance with the varying positions of the body in its movement, and means whereby when the movement of the body is stopped the opposing moments of said forces automatically adjust themselves to establish equilibrium.

Advantageously the balancing device embodies a rotary member over which is adapted to pass a flexible inextensible member, the traversable body to be balanced o functioning to exert a force on said flexible member tending to rotate the rotary member in one direction, and spring means tending to rotate said rotary member in an opposite direction, the force exerted by the spring means varying in magnitude in accordance with the position occupied by the body in its traverse and means whereby the opposing moments of force of said moving body and spring means are automatically brought 7 into equilibrium at varying or successive positions in the traversing movement of said body.

For the purpose of more fully describing the nature of this invention reference will now be made to the accompanying drawings, wherein V Figure 1 illustrates in elevation a vertically slidable window with balancing means in accordance with one embodiment of this invention applied thereto.

Figures 2, 3, 4:, 5 and 6 are views, diagrammatic in character, which illustrate various other embodiments of the invention.

In a particular embodiment of the invention same will be described byway of example as applied to a vertically slidable window such as is employed on automobiles and the like. The window 1 (see Figure 1) constitutes the traversable body or weight and has a horizontally disposed roller 2 rotatably mounted adjacent to its lower edge and conveniently carried by or accommo dated within bearing lugs 3 projecting down from a metal channel 4 of the window. Within this roller 2, which comprises a tubular member, is accommodated a coiled spring 5, one end of which is suitably connected to the tube'2 and the other to a relatively stationary axis 6, and to the exterior of said roller is connected the one end of a chain 7 which conveniently extends upwardly and is connected at its other end to a fixed frame member 8 preferably at a po sition approximately midway in the Width of the window. 4

This chain is preferably composed of flat link members, the said links being if desired of uniform length,- in which case, as the window 1 is traversed in either direction i. e. raised or lowered, and the force of the spring 5 consequently altered, the angle at which the links bear on the roller 2 is also altered. By this variation of the angular disposition of the chain links upon the roller, a cyclic variation is applied to the balancing moment by means of the weight of the body to be balanced and the arrangement is such that the effective counterbalancing moment exerted by the spring always lies intermediate the upper and lower limitations of such cyclic variation. 1 In other words, when the window is moved to any desired position in the extent of its traverse, same will when released automatically come to rest at a position where the angular disposition'of the links coacting with the roller is such as to balance the opposing forces of the window and spring.

As represented in Figure 1 the links of the chain are long, as compared with the diameter of the roller 2, with the result that when wound thereupon the effective moment applied through the chain and tending to rotate the roller varies in cycles, since the moment of such applied force, when the line including the last link then in engagement with the roller is approximately at right angles to the line in which lies that portion of the chain which is attached at .8, is much greater than when the line including such last line and that including the attached portion of the chain coincide. In the arrangement represented, where the length of the links approximates twice the diameter of the roller, a section of chain composed of three links will approximately encircle the roller once, and there will be three cyclic changes in the application of moment tending to rotate the shaft or roller 2 in opposition to the moment of the spring 5, at each complete revolution of the shaft. The moment of the spring, tending to rotate the roller, will be adjusted so as to lie between the extremes of the opposing momentappliedthrough the chain, throughout its entire range of variation; and hence it follows that in any cyclic movement of the chain relative to the roller, a point is reached where the moment of the force applied to be counterbalanced exactly equals the moment being applied to the roller by the spring. In other -words, these two moments come into equilibrium and the window or other body is counterbalanced three times at each revolution of the roller, and this is true throughout the whole range of traverse of such body.

The chain links may, however, be of pro gressively increasing length in which case the balancing of the opposing moments of the weight and spring is accomplished by reason of the variation in the length of the links and not, as in the case of links of uniform length, by the angular disposition of said links on therollera For example, if, in the application of the invention to a vertically sliding window, the links are progressively increased in length from the upper to the lower end (see Figure 2) the downward movement of the window and the consequent downwardmovement of-the roller 2 will result-in the chain beinguncoiled from said roller, and the spring by the rotation of the roller more tightly coiled. This movement gradually increases the force exerted by the spring, but to compensate for this increased spring force the gradually increased length of the chain links increases the leverage produced by said links on the roller to an extent which, when the window is released, brings the opposing moments of the window and spring into equilibrium and causes the windowto come to rest in a balanced position. The same effect is of course produced during the upward motion of the window wherein the decreasing spring effort is balanced by the decreasing moments of force obtained by the gradual shortening of the chain links.

In another modification, a chain may be employed having links which may be of uniform length but of progressively increasing thickness as shown in Figure 3. By this means it will be appreciated that during the traversing of the window or other rising and falling body and consequent coiling ofathe chain upon or uncoiling of same from the roller 2 diiferent lever actions are produced which will bring the traversing body into a state of equilibrium at varying positions in its traverse in a manner similar to that described with reference to a chain having links of progressively increasing length.

The invention is not of course restricted to its application toa sliding window but is intended to cover the provision of means for bringing to a state of equilibrium any rising and falling weight thev motionof whlch is assisted in one direction and resisted in the opposite direction by aforce of varyin magnitude, For example, arising and alling body, indicated at W, to be balanced may be connected to a flexible inextensible member 9 other than a chain .or like articulated member (see Figure 4) said member being adapted to pass over and coact with the periphery of a rotary member 10 of polygonal section and connected on the opposite side of said roller to asuitable spring S, the arrangement being such that ,at the several positions 0c:- cupied by the weight'W in its rising and fall: ing movement the rollerlO will automatically adjust itself to a position in which the angular disposition of. the sides or faces thereof engaged by the member 9 will automatically bring into equilibriumthe opposing forces of the weight and the spring.

In another arrangement (Figure 5) a roller 10 ofpolygonal section may be employed in connection with a chain or equivalent articulated member 11, while in a still 7 further arrangement (see Figure 6) the chain 11 may be passed over a circular sectioned roll- .er12, the weight W to be balanced being on both Figures ,5 and 6 connected directly or indirectly to said chainon the one side of the rollerand the s ring S being caused to exert a force on sai chain at the other side of the roller tending to resist movement of the weight in one direction and assist same in an opposite direction, the balancing of the weight being efi'ected as beforedescribed by the angular disposition of the! chain linkson the roller.

WVe claim 1. A device for balancing bodies adapted for a rising and falling. movement, by means of an inconstant balancing moment, comprisi g means exerting a balancing force, a chain; extending over a smooth .circular element,means for applying the opposing forces to the extremities of said chain and the angular disposition taken up by the linksof such chain around said circular element during traverse ofthe body tobe balanced causing cyclic variations in the moments of the forces applied by such body tothe balancing force.

2. A device for balancing bodies adapted for arising and falling movement by means of an inconstant balancing moment, comprising means. exerting a balancing force, a

chain extending over a smooth circular element, means for applying the opposing forces to the opposite ends of said chain and means whereby the angular position taken up by the links of such chain cause a cyclic variationin the moment of the forces applied to the balancing force by the weight of the body to be balanced and the eifective value of said opposing force always lying intermediate the upper and lower limits of said cyclic variation.

3. A device for balancing bodies adapted for a rising and falling movement by means of an inconstant balancing moment, comprising a spring-influencing cylindrical body mounted below the body to be balanced and traversable therewith and a chain adapted to be wound onto or from said cylindrical body on travserse of said balanced body, the angular position taken up by the links around such cylindrical body causing cyclic variations in the moments of the forces applied by the weight of the body to be balanced to said spring-influenced body.

4:. A device for balancing bodies adapted for a rising and falling movement by means of an inconstant balancing moment, comprising a spring-influenced drum mounted below the body to be balanced and traversable therewith and a chain adapted to be wound onto or from said drum on traverse of said body, the angular disposition of the links around such drum causing a cyclic variation to be applied by the weight of the body to be balanced to said spring-influenced drum and the effective balancing moment exerted by such spring always lying intermediate the upper and lower limits of such cyclic variation.

5. A device for balancing bodies adapted for a rising and falling movement by means of an inconstant balancing moment, comprising a rotatable drum below the body to be balanced and traversable therewith, a spring arranged interiorly of said drum and tending to cause rotation thereof in one direction to raise the body to be balanced, means for securing the chain at one end to said drum whereby said chain is wound onto or from such drum on traverse of the body and a stationary point above said drum to which the free end of the chain is connected, the angular positions taken up by the links of such chain around said drum causing cyclic variations in the moments of forces applied to the spring in such drum and the efiective balancing moment exerted by such spring always lying intermediate the upper and lower limits of such cyclic variation.

6. A device for balancing bodies adapted for a rising and falling movement by means of an inconstant balancing moment, comprising a rotatable drum below the body to be balanced and traversable therewith, a non-rotatable spindle on which said drum is accommodated, a channel member secured to the lower edge of the body to be balanced and carrying said non-rotatable spindle, a spring interiorly of said drum and attached at one end thereto and at the other end to said spindle, a chain secured at one'end to said drum and adapted to be wound onto or from such drum on traverse of the body and a stationary point above the spring-influenced drum to which the free end of such chain is connected, the angular position taken up by the links of such chain around said spring-influenced drum causing cyclic variations to be applied by the weight of the body to be balanced to the spring interiorly of such drum and the effective balancing moment exerted by such spring always lying intermediate the limits of such cyclic variation.

7. Means for counterbalancing a body that is arranged to have free rising'and falling movements, comprising a freely rotatable cylindrical body, means for applying to the cylindrical body a moment tending to rotate it in one direction and a chain wound upon the cylindrical body, through which the Weight of the rising and falling body is applied as a moment to rotate the cylindrical body in opposition to the spring, the links of the chain being long relative to the diameter of the cylindrical body, whereby there are cyclic variations of substantial amplitude in the moments of the force applied through the chain as it winds upon or unwinds from the cylindrical body due to the rising and falling movements of the body being counterbalanced, the counterbalancing moment being adjusted to lie between the extremes of the opposite moment transmitted through the chain.

HARRY RILEY WEBB. HARRY NEWTON WEBB. 

